ASTM C758-18

Standard Test Methods for Chemical, Mass Spectrometric, Spectrochemical, Nuclear, and Radiochemical Analysis of Nuclear-Grade Plutonium Metal

SIGNIFICANCE AND USE
4.1 These test methods are designed to show whether a given material meets the purchaser's specifications.  
4.1.1 An assay is performed to determine whether the material has the specified plutonium content.  
4.1.2 Determination of the isotopic content of the plutonium is made to establish whether the effective fissile content is in compliance with the purchaser's specifications.  
4.1.3 Impurity content is verified by a variety of methods to ensure that the maximum concentration limit of specified impurities is not exceeded. Determination of impurities is also required for calculation of the equivalent boron content (EBC).  
4.2 Fitness for Purpose of Safeguards and Nuclear Safety Applications—Methods intended for use in safeguards and nuclear safety applications shall meet the requirements specified by Guide C1068 for use in such applications.
SCOPE
1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium metal to determine compliance with specifications.  
1.2 The analytical procedures appear in the following order:    
Sections  
Dissolution Procedure  
2  
Plutonium by Controlled-Potential Coulometry  
3  
Plutonium by Amperometric Titration with Iron (II)  
2  
Plutonium by Ceric Sulfate Titration Test Method  
3  
Plutonium by Diode Array Spectrophotometry  
3  
Uranium by Arsenazo I Spectrophotometric Test Method  
8 – 10  
Thorium by Thorin Spectrophotometric Test Method  
11 – 13  
Iron by 1,10-Phenanthroline Spectrophotometric Test Method  
14 – 16  
Iron by 2,2ʹ-Bipyridyl Spectrophotometric Test Method  
17 – 23  
Impurities by ICP-AES  
Chloride by the Thiocyanate Spectrophotometric Test Method  
24 – 26  
Fluoride by Distillation-Spectrophotometric Test Method  
27–28  
Nitrogen by Distillation-Nessler Reagent Spectrophotometric Test
Method  
29–30  
Carbon by the Direct Combustion-Thermal Conductivity Test
Method  
31 – 33  
Sulfur by Distillation-Spectrophotometric Test Method  
34 – 36  
Isotopic Composition by Mass Spectrometry  
37 and 38  
Plutonium-238 Isotopic Abundance by Alpha Spectrometry  
Americium-241 by Extraction and Gamma Counting  
39 – 41  
Americium-241 by Gamma Counting  
3  
Gamma-Emitting Fission Products, Uranium, and Thorium by
Gamma-Ray Spectroscopy  
42 – 49  
Rare Earths by Copper Spark Spectrochemical Test Method  
50 – 52  
Tungsten, Niobium (Columbium), and Tantalum by Spectro-
chemical Test Method  
53 – 55  
Sample Preparation for Spectrographic Analysis for Trace Impuri-
ties  
56 – 60  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific safeguard and safety hazards statements, see Section 6.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Aug-2018
• ICS: 27.120.30 - Fissile materials and nuclear fuel technology
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.05 - Methods of Test

Relations

• Replaces: ASTM C758-04(2010) - Standard Test Methods for Chemical, Mass Spectrometric, Spectrochemical, Nuclear, and Radiochemical Analysis of Nuclear-Grade Plutonium Metal
• Effective Date: 01-Sep-2018
• Refers: ASTM C859-24 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM C1432-23 - Standard Test Method for Determination of Impurities in Plutonium: Acid Dissolution, Ion Exchange Matrix Separation, and Inductively Coupled Plasma-Atomic Emission Spectroscopic (ICP/AES) Analysis
• Effective Date: 01-Dec-2023
• Refers: ASTM C1268-23 - Standard Test Method for Quantitative Determination of ²⁴¹Am in Plutonium by Gamma-Ray Spectrometry
• Effective Date: 01-Oct-2023
• Refers: ASTM C1168-23 - Standard Practice for Preparation and Dissolution of Plutonium Materials for Analysis
• Effective Date: 01-Oct-2023
• Refers: ASTM C759-18 - Standard Test Methods for Chemical, Mass Spectrometric, Spectrochemical, Nuclear, and Radiochemical Analysis of Nuclear-Grade Plutonium Nitrate Solutions
• Effective Date: 01-Sep-2018
• Refers: ASTM C1156-18 - Standard Guide for Establishing Calibration for a Measurement Method Used to Analyze Nuclear Fuel Cycle Materials
• Effective Date: 01-Sep-2018
• Refers: ASTM C1297-18 - Standard Guide for Qualification of Laboratory Analysts for the Analysis of Nuclear Fuel Cycle Materials
• Effective Date: 01-Jul-2018
• Refers: ASTM C1415-18 - Standard Test Method for ²³⁸Pu Isotopic Abundance By Alpha Spectrometry
• Effective Date: 01-Jun-2018
• Refers: ASTM C852/C852M-16 - Standard Guide for Design Criteria for Plutonium Gloveboxes
• Effective Date: 01-Nov-2016
• Refers: ASTM C698-16 - Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Mixed Oxides ((U, Pu)O<inf>2</inf>)
• Effective Date: 01-Jun-2016
• Refers: ASTM C697-16 - Standard Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Plutonium Dioxide Powders and Pellets
• Effective Date: 01-Jun-2016
• Refers: ASTM C1168-15 - Standard Practice for Preparation and Dissolution of Plutonium Materials for Analysis
• Effective Date: 01-Sep-2015
• Refers: ASTM C1268-15 - Standard Test Method for Quantitative Determination of ²⁴¹Am in Plutonium by Gamma-Ray Spectrometry
• Effective Date: 01-Jun-2015
• Refers: ASTM C1432-15 - Standard Test Method for Determination of Impurities in Plutonium: Acid Dissolution, Ion Exchange Matrix Separation, and Inductively Coupled Plasma-Atomic Emission Spectroscopic (ICP/AES) Analysis
• Effective Date: 01-Jun-2015

Overview

ASTM C758-18: Standard Test Methods for Chemical, Mass Spectrometric, Spectrochemical, Nuclear, and Radiochemical Analysis of Nuclear-Grade Plutonium Metal establishes comprehensive procedures for verifying the composition and purity of nuclear-grade plutonium metal. Developed by ASTM Committee C26, this standard aims to determine compliance with stringent purchaser specifications regarding plutonium content, isotopic composition, and impurity levels. Its methodologies ensure that nuclear-grade plutonium meets quality requirements critical for nuclear safety and safeguards applications.

Key Topics

• Assay of Plutonium Content: Methods to quantify whether the plutonium content is within required limits.

• Isotopic Analysis: Procedures for precise determination of plutonium isotope content, essential for evaluating fissile properties.

• Impurity Analysis: Multiple analytical approaches are specified for detecting and quantifying impurities such as iron, uranium, thorium, rare earths, and other elements. This is crucial for calculating equivalent boron content and ensuring overall material quality.

• Test Techniques Included:

  • Controlled-potential coulometry
  • Amperometric titration
  • Ceric sulfate titration
  • Spectrophotometry (various reagents and elements)
  • ICP-AES for trace impurities
  • Mass spectrometry and alpha spectrometry
  • Gamma-ray spectroscopy
  • Direct combustion-thermal conductivity for carbon measurement

• Sample Preparation: Outlines robust procedures to avoid contamination and ensure reliable analytical results. All implements, reagents, and water must meet identified purity standards.

• Safety and Compliance: Special emphasis on safe handling of radioactive and toxic materials, and requirement to adhere to relevant regulatory guidelines and safety procedures.

Applications

ASTM C758-18 is vital across the nuclear industry, guiding laboratories and facilities engaged in the production, certification, and quality control of nuclear-grade plutonium metal. Key practical applications include:

• Material Acceptance and Quality Assurance: Used to verify that plutonium metal delivered meets contractual and regulatory requirements for nuclear reactor fuel fabrication and other nuclear technology uses.
• Nuclear Safeguards and Security: Supports accountability and traceability of nuclear materials in line with international safeguards, aiding in the prevention of diversion or misuse.
• Nuclear Safety Analyses: By accurately characterizing isotopic and impurity content, these test methods help ensure that the nuclear materials are fit for safe application in reactors, experimental setups, or storage.
• Regulatory Compliance: Offers essential support for compliance with requirements set forth by nuclear regulatory authorities and international standards bodies.
• Research and Development: Laboratories and research institutions depend on ASTM C758-18 for methodical analysis in the development of advanced nuclear fuels and management of plutonium stocks.

Related Standards

The methodologies in ASTM C758-18 reference or are complemented by other ASTM standards, notably:

• ASTM C697 - Test Methods for Analysis of Nuclear-Grade Plutonium Dioxide Powders and Pellets
• ASTM C698 - Test Methods for Analysis of Nuclear-Grade Mixed Oxides
• ASTM C759 - Test Methods for Plutonium Nitrate Solution Analysis
• ASTM C852/C852M - Guide for Plutonium Gloveboxes Design Criteria
• ASTM C1108, C1165, C1168, C1307, C1415, C1432 - Specific analytical and sample preparation procedures
• ASTM D1193 - Reagent Water Specification

Consultation of these related standards is encouraged for comprehensive implementation, calibration, and quality control in nuclear materials laboratories.

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Keywords: ASTM C758-18, nuclear-grade plutonium metal, plutonium analysis, isotopic composition, impurity analysis, mass spectrometric analysis, radiochemical analysis, plutonium sample preparation, nuclear safeguards, nuclear safety, ASTM standards for nuclear materials.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C758 − 18
Standard Test Methods for
Chemical, Mass Spectrometric, Spectrochemical, Nuclear,
and Radiochemical Analysis of Nuclear-Grade Plutonium
Metal
This standard is issued under the fixed designation C758; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 These test methods cover procedures for the chemical,
responsibility of the user of this standard to establish appro-
mass spectrometric, spectrochemical, nuclear, and radiochemi-
priate safety, health, and environmental practices and deter-
cal analysis of nuclear-grade plutonium metal to determine
mine the applicability of regulatory limitations prior to use.
compliance with specifications.
For specific safeguard and safety hazards statements, see
1.2 Theanalyticalproceduresappearinthefollowingorder:
Section 6.
Sections
1.5 This international standard was developed in accor-
Dissolution Procedure
dance with internationally recognized principles on standard-
Plutonium by Controlled-Potential Coulometry
ization established in the Decision on Principles for the
Plutonium by Amperometric Titration with Iron (II)
Plutonium by Ceric Sulfate Titration Test Method
Development of International Standards, Guides and Recom-
Plutonium by Diode Array Spectrophotometry
mendations issued by the World Trade Organization Technical
Uranium by Arsenazo I Spectrophotometric Test Method 8–10
Barriers to Trade (TBT) Committee.
Thorium by Thorin Spectrophotometric Test Method 11–13
Iron by 1,10-Phenanthroline Spectrophotometric Test Method 14–16
Iron by 2,2-Bipyridyl Spectrophotometric Test Method 17–23 2. Referenced Documents
Impurities by ICP-AES
2.1 ASTM Standards:
Chloride by the Thiocyanate Spectrophotometric Test Method 24–26
Fluoride by Distillation-Spectrophotometric Test Method 27–28
C697Test Methods for Chemical, Mass Spectrometric, and
Nitrogen by Distillation-Nessler Reagent Spectrophotometric Test 29–30
Spectrochemical Analysis of Nuclear-Grade Plutonium
Method
Dioxide Powders and Pellets
Carbon by the Direct Combustion-Thermal Conductivity Test 31–33
Method
C698Test Methods for Chemical, Mass Spectrometric, and
Sulfur by Distillation-Spectrophotometric Test Method 34–36
Spectrochemical Analysis of Nuclear-Grade Mixed Ox-
Isotopic Composition by Mass Spectrometry 37 and
38 ides ((U, Pu)O )
Plutonium-238 Isotopic Abundance by Alpha Spectrometry
C759Test Methods for Chemical, Mass Spectrometric,
Americium-241 by Extraction and Gamma Counting 39–41
3 Spectrochemical,Nuclear,andRadiochemicalAnalysisof
Americium-241 by Gamma Counting
Nuclear-Grade Plutonium Nitrate Solutions
Gamma-Emitting Fission Products, Uranium, and Thorium by 42–49
Gamma-Ray Spectroscopy
C852/C852MGuide for Design Criteria for Plutonium
Rare Earths by Copper Spark Spectrochemical Test Method 50–52
Gloveboxes
Tungsten, Niobium (Columbium), and Tantalum by Spectro- 53–55
chemical Test Method C859Terminology Relating to Nuclear Materials
Sample Preparation for Spectrographic Analysis for Trace Impuri- 56–60
C1009Guide for Establishing and Maintaining a Quality
ties
AssuranceProgramforAnalyticalLaboratoriesWithinthe
1.3 The values stated in SI units are to be regarded as
Nuclear Industry
standard. No other units of measurement are included in this
C1068Guide for Qualification of Measurement Methods by
standard.
a Laboratory Within the Nuclear Industry
C1108Test Method for Plutonium by Controlled-Potential
Coulometry
C1128Guide for Preparation of Working Reference Materi-
These test methods are under the jurisdiction of ASTM Committee C26 on
Nuclear Fuel Cycle and are the direct responsibility of Subcommittee C26.05 on
als for Use in Analysis of Nuclear Fuel Cycle Materials
Methods of Test.
Current edition approved Sept. 1, 2018. Published October 2018. Originally
approved in 1973. Last previous edition approved in 2010 as C758–04 (2010). For referenced ASTM Standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/C0758-18. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Discontinued as of February 10, 1998. Standardsvolume information, refer to the standard’s Document Summary page on
Discontinued as of November 15, 1992 the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C758 − 18
C1156Guide for Establishing Calibration for a Measure- cal Society, where such specifications are available. Other
ment Method Used toAnalyze Nuclear Fuel Cycle Mate- grades may be used, provided it is first ascertained that the
rials reagent is of sufficient high purity to permit its use without
C1165 Test Method for Determining Plutonium by lessening the accuracy of the determination.
Controlled-Potential Coulometry in H SO at a Platinum
2 4
5.2 Purity of Water—Unless otherwise indicated, reference
Working Electrode
towatershallbeunderstoodtomeanreagentwaterconforming
C1168PracticeforPreparationandDissolutionofPlutonium
to Specification D1193.
Materials for Analysis
C1206Test Method for Plutonium by Iron (II)/Chromium
6. Safety Hazards
(VI) Amperometric Titration (Withdrawn 2015)
6.1 Since plutonium bearing materials are radioactive and
C1210Guide for Establishing a Measurement System Qual-
toxic,adequatelaboratoryfacilities,glovedboxes,fumehoods,
ity Control Program for Analytical Chemistry Laborato-
etc., along with safe techniques, must be used in handling
ries Within the Nuclear Industry
samplescontainingthesematerials.Adetaileddiscussionofall
C1235 Test Method for Plutonium by Titanium(III)/
the precautions necessary is beyond the scope of these test
Cerium(IV) Titration (Withdrawn 2005)
methods; however, personnel who handle these materials
C1268 Test Method for Quantitative Determination of
should be familiar with such safe handling practices as are
Am in Plutonium by Gamma-Ray Spectrometry
given in Guide C852/C852M and in Refs. (1-3).
C1297Guide for Qualification of Laboratory Analysts for
the Analysis of Nuclear Fuel Cycle Materials
7. Sampling
C1307Test Method for PlutoniumAssay by Plutonium (III)
7.1 In the absence of ASTM test methods for sampling
Diode Array Spectrophotometry
238 plutonium metal, alternative techniques are recommended
C1415Test Method for Pu Isotopic Abundance By Alpha
(3-6).
Spectrometry
C1432Test Method for Determination of Impurities in 7.2 Cognizance shall be taken of the fact that various
Plutonium: Acid Dissolution, Ion Exchange Matrix impuritiescanbeintroducedintosamplesduringtheprocessof
Separation, and Inductively Coupled Plasma-Atomic sampling. The particular impurities introduced are a function
Emission Spectroscopic (ICP/AES) Analysis of the method of sampling (for example, iron and alloying
D1193Specification for Reagent Water elementsindrillturning,oxygenorcomponentsofcoolingoil,
or both, from lathe turnings, etc.). It is necessary for the
3. Terminology
purchaser and the seller to recognize this possibility for
contaminationduringsamplingandmutuallyagreeonthemost
3.1 For definitions of terms used in this test method but not
suitable method.
defined herein, refer to Terminology C859.
7.3 Samplesizeshallbesufficienttoperformthefollowing:
4. Significance and Use
7.3.1 Quality verification tests at the seller’s plant,
4.1 These test methods are designed to show whether a
7.3.2 Acceptance tests at the purchaser’s plant, and
given material meets the purchaser’s specifications.
7.3.3 Referee tests in the event these become necessary.
4.1.1 An assay is performed to determine whether the
7.4 All samples shall be identified clearly by the seller’s
material has the specified plutonium content.
button number and by the lot number, and all pieces of metal
4.1.2 Determinationoftheisotopiccontentoftheplutonium
in that lot shall be identified clearly by the lot number and the
is made to establish whether the effective fissile content is in
piece number.
compliance with the purchaser’s specifications.
7.4.1 Alotisdefinedasasinglebutton,fractionofabutton,
4.1.3 Impurity content is verified by a variety of methods to
or multiple castings from a single melt of plutonium metal.
ensure that the maximum concentration limit of specified
Buttons, fractions of buttons, or multiple castings are usually
impurities is not exceeded. Determination of impurities is also
supplied in pieces of not less than 50 g. All pieces shall be
requiredforcalculationoftheequivalentboroncontent(EBC).
identified positively as coming from a particular button,
4.2 Fitness for Purpose of Safeguards and Nuclear Safety
fraction of a button, or casting.
Applications—Methods intended for use in safeguards and
7.4.2 A lot shall normally not be less than 1800 g of
nuclear safety applications shall meet the requirements speci-
plutonium, except as necessary to meet some special require-
fied by Guide C1068 for use in such applications.
ment. The maximum size of a lot will depend on equipment
size of the producer and criticality considerations.
5. Reagents and Materials
5.1 Purity of Reagents—Reagent grade chemicals shall be
Reagent Chemicals, American Chemical Society Specifications, American
used in all test methods. Unless otherwise indicated, it is
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
intended that all reagents shall conform to the specifications of
listed by the American Chemical Society, see Analar Standards for Laboratory
theCommitteeonAnalyticalReagentsoftheAmericanChemi-
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
and National Foundary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD.
5 7
The last approved version of this historical standard is referenced on Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
www.astm.org. these test methods.
C758 − 18
DISSOLUTION PROCEDURE
A, B = constants in linear calibration equation,
(This practice is replaced by Standard Practice C1168).
D = dilution factor= V/E
PLUTONIUM BY CONTROLLED-POTENTIAL where:
COULOMETRY
V = volume in which sample solution was diluted, mL, and
(This test method was discontinued in 1992 and replaced by
E = volume of aliquot of V used for uranium determination,
Test Method C1165) mL,
where:
PLUTONIUM BY CONTROLLED-POTENTIAL
COULOMETRY
W = weight of test portion of Pu metal sample, g, and
(With appropriate sample preparation, controlled-potential Y = a− b=corrected absorbance of sample,
coulometric measurement as described in Test Method C1108
where:
may be used for plutonium determination.)
a = absorbance of sample solution, and
b = average absorbance of duplicate calibration blanks.
PLUTONIUM BY AMPEROMETRIC TITRATION
WITH IRON(II)
THORIUM BY THORIN SPECTROPHOTOMETRIC
(This test method was discontinued in 1992 and replaced by
TEST METHOD
Test Method C1206)
PLUTONIUM BY CERIC SULFATE TITRATION TEST 11. Scope
METHOD
11.1 This test method covers the determination of thorium
(This test method is replaced by Test Method C1235.)
intherangefrom10to150µg/gofplutoniuminnuclear-grade
plutonium metal.
TEST METHOD FOR PLUTONIUM ASSAY BY
PLUTONIUM(III) DIODE ARRAY
12. Summary of Test Method
SPECTROPHOTOMETRY
(With appropriate sample preparation, the measurement 12.1 To an acid solution of plutonium metal, lanthanum is
described in Test Method C1307 may be used for plutonium added as a carrier and is precipitated along with thorium as
determination.) insolublefluoride,whiletheplutoniumremainsinsolutionand
isdecantedaftercentrifugationofthesample.Thethoriumand
URANIUM BY ARSENAZO I
lanthanumfluorideprecipitatesaredissolvedinperchloricacid
SPECTROPHOTOMETRIC TEST METHOD
andtheabsorbanceofthethorium-Thorincomplexismeasured
at a wavelength of 545 nm versus a reference solution. The
8. Scope
molar absorptivity of the colored complex is of 15 600 for
8.1 Thistestmethodcoversthedeterminationofuraniumin
thorium concentration in the range from 5 to 70 µg Th/10 mL
the range from 300 to 3000 µg/g of plutonium.
of solution.
9. Summary of Test Method
13. Procedure
9.1 Plutonium metal dissolved in 6 N HCl is reduced to
13.1 Transfer an aliquot of solution of plutonium metal,
Pu(III) with hydroxylamine hydrochloride. The uranium and
plutonium are separated by anion exchange; then the uranium prepared in accordance with Sections 6 and 7 of these test
methods, that contains from 10 to 70 µg of thorium and no
is determined by measuring the absorbance of the U(VI)-
greater than 500 mg of plutonium, into a 20-mL beaker.
Arsenazo I complex in a 1-cm cell at a wavelength of 600 nm
versus a reagent blank.
13.2 Determine the thorium concentration in accordance
with the appropriate sections of Test Methods C759.
10. Procedure
NOTE 2—Since the starting sample is plutonium metal the following
10.1 Transfer an aliquot of sample solution, prepared in
equation for calculating the thorium concentration must be substituted for
accordance with Practice C1168, that contains approximately
the equation given in 49.3 of Test Methods C759:
70 mg of plutonium, to a 50-mLbeaker and add 1 mLof nitric
Th, µg/g ofPu 5 Y 2 B D/AW (2)
~ !
acid (sp gr 1.42) and heat to boiling. Proceed with the
determination of uranium in accordance with the appropriate
where:
sections of Test Methods C759.
A, B = constants in the linear calibration equation,
W = sample weight, g,
NOTE 1—Since the sample starts as plutonium metal and is then
dissolved in acid and diluted to volume and an aliquot of this solution D = dilution factor= V/E
taken for the uranium determination, the following equation for calculat-
where:
ing the uranium concentration must be substituted for the equation given
in 28.1 of Test Methods C759:
V = volume to which dissolved plutonium metal is diluted,
R 5 ~Y 2 B!D/AW (1) mL, and
E = volume of aliquot of V taken for determination, mL,
where:
R = micrograms U per gram Pu, Y = a− b=corrected absorbance of sample solution
C758 − 18
where: 20. Reagents and Materials
a = absorbance of sample solution, and
20.1 Chloroform.
b = average absorbance from the duplicate reagent blanks
20.2 2,2ʹ-Bipyridyl Solution, 2% aqueous solution.
(see section 47.2.1 of Test Methods C759).
20.3 Hydrochloric Acid (1 + 1)—Add500mLofHCl(spgr
IRON BY 1,10-PHENANTHROLINE
1.19), to 500 mL of water.
SPECTROPHOTOMETRIC TEST METHOD
20.4 Iron, Standard Solution (50 µg/mL)—To prepare, dis-
solve 1.000 g of pure iron metal in 25 mL of HCl (6 N), cool,
14. Scope
and dilute to 1 Lwith water (Note 5). Pipet 25 mLof the iron
14.1 This test method covers the determination of micro-
solution, 1.00 mg/mL, into a 500-mL flask, add 10 mL of 6 N
gram quantities of iron in nuclear-grade plutonium metal.
HCl,anddilutetovolumewithwater.Thissolutioncontains50
µg of iron/mL.
15. Summary of Test Method
20.5 Reagent Composite—Mix 250 mL of reducing
15.1 Ferricironisreducedtoferrousironwithhydroxylam-
solutions, 250 mLof α,αʹ-dipyridyl solution, 50 mLof wetting
ine hydrochloride. Solutions of 1,10-phenanthroline and ac-
agent,and500mLofsodiumacetatebuffersolutions(Note4).
etate buffer are added and the pH adjusted to 3.5 to 4.5. The
+2
20.6 Reducing Solution—Dissolve 108 g of hydroxylamine
absorbance of the red-orange complex [(C H N ) Fe] is
12 8 2 3
hydrochloride in water, add 600 mLof glacial acetic acid, and
read at 508 nm against a sample blank containing all of the
dilute to 2 L with water.
reagents except the 1,10-phenanthroline.
20.7 Sodium Acetate Buffer Solutions—Dissolve 2270 g (5
16. Procedure
lb) of sodium acetate in 8 L of water.
16.1 Dissolve a sample of plutonium metal in HCl as
20.8 Wetting Agent—Dilute 20 mL of concentrate to 2 L
described in Test Method C1206.
with water.
16.2 Determine the iron content in accordance with the
NOTE 4—This composite solution is stable for 25 h.
appropriate sections of Test Methods C759. NOTE5—Heatslowlyandcoverbeakerwithwatchglasstopreventloss
of iron during dissolution.
NOTE 3—Since the starting sample is plutonium metal, the following
equation must be substituted for the equation given in Section 57 of Test
21. Procedure
Methods C759 in order to calculate the iron concentration of the sample:
21.1 Weigh, in duplicate, samples of plutonium metal that
Fe, µg/g Pu 5 CD/W (3)
containfrom25to75µgofiron,transferto125-mLextraction
where:
bottles, and dissolve the metal in 1 mL of 6 N HCl.
C = micrograms of Fe from calibration curve,
21.2 Add 20 mLof composite reagent, mix thoroughly, and
W = sample weight, g, and
allow 30 min for ferric iron to be reduced.
D = dilution factor= V/A
21.3 Adjust the solution to pH 4.3 with sodium acetate
where:
solution.
V = volume to which dissolved sample is diluted, and
21.4 Add 25 mL of chloroform from an automatic dispens-
A = aliquot of V that was used for iron determination.
ing pipet. Invert the bottle 20 to 25 times but do not shake
vigorously.
IRON B 2,2ʹ-BIPYRIDYL SPECTROPHOTOMETRIC
TEST METHOD
NOTE 6—Take care to avoid forming an emulsion.
21.5 Separate the chloroform phase and measure the absor-
17. Section
bance against distilled water at a wavelength of 520 nm.
17.1 Thistestmethodcoversthedeterminationofironinthe
21.6 Determine a reagent blank using all reagents but
concentration range from 20 to 100 µg for samples of nuclear-
omitting the sample.
grade plutonium metal.
21.7 Prepareacalibrationcurve,orcalculatemicrogramsof
18. Summary of Test Method iron per absorbance unit, by processing a series of solutions
containing various amounts of iron standard from 5 to 200 µg
18.1 The plutonium metal is dissolved in HCl, the solution
of iron in accordance with the procedure outlined in 21.1 –
is buffered with sodium acetate, and the iron(II) as α,αʹ-
21.5.
dipyridyl complex is extracted into chloroform and the absor-
bance measured at 520 nm against distilled water.
22. Calculation
22.1 Calculate the iron content of the sample as follows:
19. Apparatus
Fe, µg/g 5 A 2 A F/W (4)
~ !
19.1 Spectrophotometer, visible range. 1
19.2 Extraction Bottles, glass-stopped, 125-mL volume.
19.3 Pipets, 10 and 25-mL, automatic dispensing. Tergitol, a trademark of Union Carbide Corp., is a satisfactory wetting agent.
C758 − 18
where: 28. Procedure
A = absorbance for sample,
28.1 Use an aliquot of distillate prepared by steam distilla-
A = absorbance of reagent blank,
tion in Section 38 and proceed with the determination in
F = micrograms of iron per absorbance unit as determined
accordance with the appropriate sections of Test Methods
with calibration standards, and
C759.
W = sample weight, g.
28.2 Sincetheoriginalsampleisplutoniummetalinsteadof
23. Precision and Bias
a solution, omit the term P from the equation given in Section
73 of Test Methods C759 for the calculation of the fluoride
23.1 Arelative standard deviation of 610% of the amount
content of the sample.
present has been observed for iron in plutonium in the range
from 25 to 500 ppm.
NITROGEN BY DISTILLATION-NESSLER REAGENT
23.2 This test method is unbiased when chemical standard-
SPECTROPHOTOMETRIC TEST METHOD
ization is used.
29. Scope
IMPURITIES BY ICP-AES
29.1 This test method covers the determination of 5 to 100
(Cationic impurities may be determined using Test Method
C1432 (Impurities by ICP-AES) with appropriate sample µg/g nitride nitrogen in plutonium metal samples.
preparation and instrumentation).
30. Sample Preparation and Analysis
CHLORIDE BY THE THIOCYANATE
30.1 Transferaweighedsampleintherangefrom1.0to1.2
SPECTROPHOTOMETRI
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C758 − 04 (Reapproved 2010) C758 − 18
Standard Test Methods for
Chemical, Mass Spectrometric, Spectrochemical, Nuclear,
and Radiochemical Analysis of Nuclear-Grade Plutonium
Metal
This standard is issued under the fixed designation C758; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical
analysis of nuclear-grade plutonium metal to determine compliance with specifications.
1.2 The analytical procedures appear in the following order:
Sections
Dissolution Procedure
Plutonium by Controlled-Potential Coulometry
Plutonium by Amperometric Titration with Iron (II)
Plutonium by Ceric Sulfate Titration Test Method
Plutonium by Diode Array Spectrophotometry
Uranium by Arsenazo I Spectrophotometric Test Method 8 – 10
Thorium by Thorin Spectrophotometric Test Method 11 – 13
Iron by 1,10-Phenanthroline Spectrophotometric Test Method 14 – 16
Iron by 2,2-Bipyridyl Spectrophotometric Test Method 17 – 23
Impurities by ICP-AES
Chloride by the Thiocyanate Spectrophotometric Test Method 24 – 26
Fluoride by Distillation-Spectrophotometric Test Method 27–28
Nitrogen by Distillation-Nessler Reagent Spectrophotometric Test 29–30
Method
Carbon by the Direct Combustion-Thermal Conductivity Test 31 – 33
Method
Sulfur by Distillation-Spectrophotometric Test Method 34 – 36
Isotopic Composition by Mass Spectrometry 37 and
Plutonium-238 Isotopic Abundance by Alpha Spectrometry
Americium-241 by Extraction and Gamma Counting 39 – 41
Americium-241 by Gamma Counting
Gamma-Emitting Fission Products, Uranium, and Thorium by 42 – 49
Gamma-Ray Spectroscopy
Rare Earths by Copper Spark Spectrochemical Test Method 50 – 52
Tungsten, Niobium (Columbium), and Tantalum by Spectro- 53 – 55
chemical Test Method
Sample Preparation for Spectrographic Analysis for Trace Impuri 56 – 60
ties
Sample Preparation for Spectrographic Analysis for Trace Impuri- 56 – 60
ties
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. For specific safeguard and safety hazards statements, see Section 6.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
These test methods are under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and are the direct responsibility of Subcommittee C26.05 on Methods
of Test.
Current edition approved Jan. 1, 2010Sept. 1, 2018. Published February 2010October 2018. Originally approved in 1973. Last previous edition approved in 20042010 as
C758 – 04.C758 – 04 (2010). DOI: 10.1520/C0758-10.10.1520/C0758-18.
Discontinued as of February 10, 1998.
Discontinued as of November 15, 1992
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C758 − 18
2. Referenced Documents
2.1 ASTM Standards:
C697 Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Plutonium Dioxide
Powders and Pellets
C698 Test Methods for Chemical, Mass Spectrometric, and Spectrochemical Analysis of Nuclear-Grade Mixed Oxides ((U,
Pu)O )
C759 Test Methods for Chemical, Mass Spectrometric, Spectrochemical, Nuclear, and Radiochemical Analysis of Nuclear-
Grade Plutonium Nitrate Solutions
C852C852/C852M Guide for Design Criteria for Plutonium Gloveboxes
C859 Terminology Relating to Nuclear Materials
C1009 Guide for Establishing and Maintaining a Quality Assurance Program for Analytical Laboratories Within the Nuclear
Industry
C1068 Guide for Qualification of Measurement Methods by a Laboratory Within the Nuclear Industry
C1108 Test Method for Plutonium by Controlled-Potential Coulometry
C1128 Guide for Preparation of Working Reference Materials for Use in Analysis of Nuclear Fuel Cycle Materials
C1156 Guide for Establishing Calibration for a Measurement Method Used to Analyze Nuclear Fuel Cycle Materials
C1165 Test Method for Determining Plutonium by Controlled-Potential Coulometry in H SO at a Platinum Working Electrode
2 4
C1168 Practice for Preparation and Dissolution of Plutonium Materials for Analysis
C1206 Test Method for Plutonium by Iron (II)/Chromium (VI) Amperometric Titration (Withdrawn 2015)
C1210 Guide for Establishing a Measurement System Quality Control Program for Analytical Chemistry Laboratories Within
the Nuclear Industry
C1235 Test Method for Plutonium by Titanium(III)/Cerium(IV) Titration (Withdrawn 2005)
C1268 Test Method for Quantitative Determination of Am in Plutonium by Gamma-Ray Spectrometry
C1297 Guide for Qualification of Laboratory Analysts for the Analysis of Nuclear Fuel Cycle Materials
C1307 Test Method for Plutonium Assay by Plutonium (III) Diode Array Spectrophotometry
C1415 Test Method for Pu Isotopic Abundance By Alpha Spectrometry
C1432 Test Method for Determination of Impurities in Plutonium: Acid Dissolution, Ion Exchange Matrix Separation, and
Inductively Coupled Plasma-Atomic Emission Spectroscopic (ICP/AES) Analysis
D1193 Specification for Reagent Water
3. Terminology
3.1 For definitions of terms used in this test method but not defined herein, refer to Terminology C859.
4. Significance and Use
4.1 These test methods are designed to show whether a given material meets the purchaser’s specifications.
4.1.1 An assay is performed to determine whether the material has the specified plutonium content.
4.1.2 Determination of the isotopic content of the plutonium is made to establish whether the effective fissile content is in
compliance with the purchaser’s specifications.
4.1.3 Impurity content is verified by a variety of methods to ensure that the maximum concentration limit of specified impurities
is not exceeded. Determination of impurities is also required for calculation of the equivalent boron content (EBC).
4.2 Fitness for Purpose of Safeguards and Nuclear Safety Applications—Methods intended for use in safeguards and nuclear
safety applications shall meet the requirements specified by Guide C1068 for use in such applications.
4. Committee C-26 Safeguards Statement
4.1 The material (plutonium metal) to which these test methods apply is subject to nuclear safeguards regulations governing its
possession and use. The following analytical procedures in these test methods have been designed as technically acceptable for
generating safeguards accountability measurement data: Plutonium by Controlled-Potential Coulometry; Plutonium by Ceric
Sulfate Titration; Plutonium by Amperometric Titration with Iron(II); Plutonium by Diode Array Spectrophotometry and Isotopic
Composition by Mass Spectrometry.
4.2 When used in conjunction with appropriate Certified Reference Materials (CRMs), these procedures can demonstrate
traceability to the national measurement base. However, adherence to these procedures does not automatically guarantee regulatory
acceptance of the resulting safeguards measurements. It remains the sole responsibility of the user of these test methods to assure
that their application to safeguards has the approval of the proper regulatory authorities.
For referenced ASTM Standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standardsvolume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
C758 − 18
5. Reagents and Materials
5.1 Purity of Reagents—Reagent grade chemicals shall be used in all test methods. Unless otherwise indicated, it is intended
that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society,
where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficient
high purity to permit its use without lessening the accuracy of the determination.
5.2 Purity of Water—Unless otherwise indicated, reference to water shall be understood to mean reagent water conforming to
Specification D1193.
6. Safety Hazards
6.1 Since plutonium bearing materials are radioactive and toxic, adequate laboratory facilities, gloved boxes, fume hoods, etc.,
along with safe techniques, must be used in handling samples containing these materials. A detailed discussion of all the
precautions necessary is beyond the scope of these test methods; however, personnel who handle these materials should be familiar
with such safe handling practices as are given in Guide C852C852/C852M and in Refs. (1-3).
7. Sampling
7.1 In the absence of ASTM test methods for sampling plutonium metal, alternative techniques are recommended (3-6).
7.2 Cognizance shall be taken of the fact that various impurities can be introduced into samples during the process of sampling.
The particular impurities introduced are a function of the method of sampling (for example, iron and alloying elements in drill
turning, oxygen or components of cooling oil, or both, from lathe turnings, etc.). It is necessary for the purchaser and the seller
to recognize this possibility for contamination during sampling and mutually agree on the most suitable method.
7.3 Sample size shall be sufficient to perform the following:
7.3.1 Quality verification tests at the seller’s plant,
7.3.2 Acceptance tests at the purchaser’s plant, and
7.3.3 Referee tests in the event these become necessary.
7.4 All samples shall be identified clearly by the seller’s button number and by the lot number, and all pieces of metal in that
lot shall be identified clearly by the lot number and the piece number.
7.4.1 A lot is defined as a single button, fraction of a button, or multiple castings from a single melt of plutonium metal. Buttons,
fractions of buttons, or multiple castings are usually supplied in pieces of not less than 50 g. All pieces shall be identified positively
as coming from a particular button, fraction of a button, or casting.
7.4.2 A lot shall normally not be less than 1800 g of plutonium, except as necessary to meet some special requirement. The
maximum size of a lot will depend on equipment size of the producer and criticality considerations.
DISSOLUTION PROCEDURE
(This practice is replaced by Standard Practice C1168).
PLUTONIUM BY CONTROLLED-POTENTIAL COULOMETRY
(This test method was discontinued in 1992 and replaced by Test Method C1165)
PLUTONIUM BY CONTROLLED-POTENTIAL COULOMETRY
(With appropriate sample preparation, controlled-potential coulometric measurement as described in Test Method C1108 may
be used for plutonium determination.)
PLUTONIUM BY AMPEROMETRIC TITRATION WITH IRON(II)
(This test method was discontinued in 1992 and replaced by Test Method C1206)
PLUTONIUM BY CERIC SULFATE TITRATION TEST METHOD
(This test method is replaced by Test Method C1235.)
TEST METHOD FOR PLUTONIUM ASSAY BY PLUTONIUM(III) DIODE ARRAY SPECTROPHOTOMETRY
(With appropriate sample preparation, the measurement described in Test Method C1307 may be used for plutonium
determination.)
Reagent Chemicals, American Chemical Society Specifications,” American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by
the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the UnitesUnited States Pharmacopeia and National
Foundary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
The boldface numbers in parentheses refer to the list of references at the end of these test methods.
C758 − 18
URANIUM BY ARSENAZO I SPECTROPHOTOMETRIC TEST METHOD
8. Scope
8.1 This test method covers the determination of uranium in the range from 300 to 3000 μg/g of plutonium.
8. Scope
8.1 This test method covers the determination of uranium in the range from 300 to 3000 μg/g of plutonium.
9. Summary of Test Method
9.1 Plutonium metal dissolved in 6 N HCl is reduced to Pu(III) with hydroxylamine hydrochloride. The uranium and plutonium
are separated by anion exchange; then the uranium is determined by measuring the absorbance of the U(VI)-Arsenazo I complex
in a 1-cm cell at a wavelength of 600 nm versus a reagent blank.
10. Procedure
10.1 Transfer an aliquot of sample solution, prepared in accordance with Practice C1168, that contains approximately 70 mg
of plutonium, to a 50-mL beaker and add 1 mL of nitric acid (sp gr 1.42) and heat to boiling. Proceed with the determination of
uranium in accordance with the appropriate sections of Test Methods C759.
NOTE 1—Since the sample starts as plutonium metal and is then dissolved in acid and diluted to volume and an aliquot of this solution taken for the
uranium determination, the following equation for calculating the uranium concentration must be substituted for the equation given in 28.1 of Test
Methods C759:
R 5 Y 2 B D/AW (1)
~ !
where:
R = micrograms U per gram Pu,
A, B = constants in linear calibration equation,
D = dilution factor = V/E
where:
V = volume in which sample solution was diluted, mL, and
E = volume of aliquot of V used for uranium determination, mL,
where:
W = weight of test portion of Pu metal sample, g, and
Y = a − b = corrected absorbance of sample,
where:
a = absorbance of sample solution, and
b = average absorbance of duplicate calibration blanks.
THORIUM BY THORIN SPECTROPHOTOMETRIC TEST METHOD
11. Scope
11.1 This test method covers the determination of thorium in the range from 10 to 150 μg/g of plutonium in nuclear-grade
plutonium metal.
11. Scope
11.1 This test method covers the determination of thorium in the range from 10 to 150 μg/g of plutonium in nuclear-grade
plutonium metal.
12. Summary of Test Method
12.1 To an acid solution of plutonium metal, lanthanum is added as a carrier and is precipitated along with thorium as insoluble
fluoride, while the plutonium remains in solution and is decanted after centrifugation of the sample. The thorium and lanthanum
fluoride precipitates are dissolved in perchloric acid and the absorbance of the thorium-Thorin complex is measured at a
wavelength of 545 nm versus a reference solution. The molar absorptivity of the colored complex is of 15 600 for thorium
concentration in the range from 5 to 70 μg Th/10 mL of solution.
13. Procedure
13.1 Transfer an aliquot of solution of plutonium metal, prepared in accordance with Sections 6 and 7 of these test methods,
that contains from 10 to 70 μg of thorium and no greater than 500 mg of plutonium, into a 20-mL beaker.
C758 − 18
13.2 Determine the thorium concentration in accordance with the appropriate sections of Test Methods C759.
NOTE 2—Since the starting sample is plutonium metal the following equation for calculating the thorium concentration must be substituted for the
equation given in 49.3 of Test Methods C759:
Th, µg/g of Pu 5 ~Y 2 B!D/AW (2)
where:
A, B = constants in the linear calibration equation,
W = sample weight, g,
D = dilution factor = V/E
where:
V = volume to which dissolved plutonium metal is diluted, mL, and
E = volume of aliquot of V taken for determination, mL,
Y = a − b = corrected absorbance of sample solution
where:
a = absorbance of sample solution, and
b = average absorbance from the duplicate reagent blanks (see section 47.2.1 of Test Methods C759).
IRON BY 1,10-PHENANTHROLINE SPECTROPHOTOMETRIC TEST METHOD
14. Scope
14.1 This test method covers the determination of microgram quantities of iron in nuclear-grade plutonium metal.
14. Scope
14.1 This test method covers the determination of microgram quantities of iron in nuclear-grade plutonium metal.
15. Summary of Test Method
15.1 Ferric iron is reduced to ferrous iron with hydroxylamine hydrochloride. Solutions of 1,10-phenanthroline and acetate
+2
buffer are added and the pH adjusted to 3.5 to 4.5. The absorbance of the red-orange complex [(C H N ) Fe] is read at 508 nm
12 8 2 3
against a sample blank containing all of the reagents except the 1,10-phenanthroline.
16. Procedure
16.1 Dissolve a sample of plutonium metal in HCl as described in Test Method C1206.
16.2 Determine the iron content in accordance with the appropriate sections of Test Methods C759.
NOTE 3—Since the starting sample is plutonium metal, the following equation must be substituted for the equation given in Section 57 of Test Methods
C759 in order to calculate the iron concentration of the sample:
Fe, µg/g Pu 5 CD/W (3)
where:
C = micrograms of Fe from calibration curve,
W = sample weight, g, and
D = dilution factor = V/A
where:
V = volume to which dissolved sample is diluted, and
A = aliquot of V that was used for iron determination.
IRON B 2,2ʹ-BIPYRIDYL SPECTROPHOTOMETRIC TEST METHOD
17. Scope
17.1 This test method covers the determination of iron in the concentration range from 20 to 100 μg for samples of nuclear-grade
plutonium metal.
17. Section
17.1 This test method covers the determination of iron in the concentration range from 20 to 100 μg for samples of nuclear-grade
plutonium metal.
C758 − 18
18. Summary of Test Method
18.1 The plutonium metal is dissolved in HCl, the solution is buffered with sodium acetate, and the iron(II) as α,αʹ-dipyridyl
complex is extracted into chloroform and the absorbance measured at 520 nm against distilled water.
19. Apparatus
19.1 Spectrophotometer, visible range.
19.2 Extraction Bottles, glass-stopped, 125-mL volume.
19.3 Pipets, 10 and 25-mL, automatic dispensing.
20. Reagents and Materials
20.1 Chloroform.
20.2 2,2ʹ-Bipyridyl Solution, 2 % aqueous solution.
20.3 Hydrochloric Acid (1 + 1)—Add 500 mL of HCl (sp gr 1.19), to 500 mL of water.
20.4 Iron, Standard Solution (50 μg/mL)—To prepare, dissolve 1.000 g of pure iron metal in 25 mL of HCl (6 N), cool, and
dilute to 1 L with water (Note 5). Pipet 25 mL of the iron solution, 1.00 mg/mL, into a 500-mL flask, add 10 mL of 6 N HCl, and
dilute to volume with water. This solution contains 50 μg of iron/mL.
20.5 Reagent Composite—Mix 250 mL of reducing solutions, 250 mL of α,αʹ-dipyridyl solution, 50 mL of wetting agent, and
500 mL of sodium acetate buffer solutions (Note 4).
20.6 Reducing Solution—Dissolve 108 g of hydroxylamine hydrochloride in water, add 600 mL of glacial acetic acid, and dilute
to 2 L with water.
20.7 Sodium Acetate Buffer Solutions—Dissolve 2270 g (5 lb) of sodium acetate in 8 L of water.
20.8 Wetting Agent—Dilute 20 mL of concentrate to 2 L with water.
NOTE 4—This composite solution is stable for 25 h.
NOTE 5—Heat slowly and cover beaker with watchglass to prevent loss of iron during dissolution.
21. Procedure
21.1 Weigh, in duplicate, samples of plutonium metal that contain from 25 to 75 μg of iron, transfer to 125-mL extraction
bottles, and dissolve the metal in 1 mL of 6 N HCl.
21.2 Add 20 mL of composite reagent, mix thoroughly, and allow 30 min for ferric iron to be reduced.
21.3 Adjust the solution to pH 4.3 with sodium acetate solution.
21.4 Add 25 mL of chloroform from an automatic dispensing pipet. Invert the bottle 20 to 25 times but do not shake vigorously.
NOTE 6—Take care to avoid forming an emulsion.
21.5 Separate the chloroform phase and measure the absorbance against distilled water at a wavelength of 520 nm.
21.6 Determine a reagent blank using all reagents but omitting the sample.
21.7 Prepare a calibration curve, or calculate micrograms of iron per absorbance unit, by processing a series of solutions
containing various amounts of iron standard from 5 to 200 μg of iron in accordance with the procedure outlined in 21.1 – 21.5.
22. Calculation
22.1 Calculate the iron content of the sample as follows:
Fe, µg/g5 ~A 2 A !F/W (4)
where:
A = absorbance for sample,
A = absorbance of reagent blank,
F = micrograms of iron per absorbance unit as determined with calibration standards, and
W = sample weight, g.
23. Precision and Bias
23.1 A relative standard deviation of 610 % of the amount present has been observed for iron in plutonium in the range from
25 to 500 ppm.
Tergitol, a trademark of Union Carbide Corp., is a satisfactory wetting agent.
C758 − 18
23.2 This test method is unbiased when chemical standardization is used.
IMPURITIES BY ICP-AES
(Cationic impurities may be determined using Test Method C1432 (Impurities by ICP-AES) with appropriate sample prepara-
tion and instrumentation).
CHLORIDE BY THE THIOCYANATE SPECTROPHOTOMETRIC TEST METHOD
24. Scope
24.1 This test method covers the determination of chloride in a nuclear-grade plutonium metal.
24. Scope
24.1 This test method covers the determination of chloride in a nuclear-grade plutonium metal.
25. Summary of Test Method
25.1 An aliquot of plutonium metal sample dissolved in 1.5 M sulfuric acid is mixed with a solution containing ferrous
ammonium sulfate, sulfamic acid, phosphoric acid, and sulfuric acid, and the chloride is steam distilled at a temperature of 140°C
(Note 7). An aliquot of the distillate is mixed with ferric ammonium sulfate and mercuric thiocyanate solutions. Thiocyanate ion
is released in direct proportion to the chloride ion concentration. The absorbance o
...